Microsoft has applied for a patent on a new type of physical keyboard called "Keyboard Gesturing" that could actually display different key icons depending on how you're using it. For instance, if you're playing a game, the center row of buttons could show buttons for firing, moving, jumping, and so on instead of letters. When you're composing an email, the letters would re-appear.
"Keyboard gesturing on an input device of a computing system is herein provided. One exemplary computing system includes a host computing device and an input device including one or more keys. The host computing device includes a gesture-recognition engine that's configured to recognize a gesture from touch input reported from a touch-detection engine. The touch-detection engine is configured to detect a touch input directed at a key of the input device. The host computing device further includes an input engine that's configured to interpret a key-activation message based on gesture recognized by gesture-recognition engine, where the key-activation message is generated by a key-activation engine of the input device in response to activation of the key."
The patent also covers touch-sensitive keys, which let you change the function of a key with a gesture. For instance, you may be able to capitalize a letter by dragging up so that a "q" becomes a "Q."